The Fresh Loaf

A Community of Amateur Bakers and Artisan Bread Enthusiasts.

Making a Proofing box

sandydog's picture

Making a Proofing box

I have seen many posts on this subject and I want to make my own proofing box.

My friend, and fellow baker has a box (Big enough for 2 small bannetons and a cup of water) made of polystyrene insulating material.   It is heated via a 40 watt light bulb in the (Removable) lid of the box, and the temperature is manually controlled by a dimmer switch. This is fine when he is present/awake for short term proofing/bulk fermentation, as temperatures can be monitored easily, but not so good if you wish to bulk ferment dough or final proof loaves overnight.

Looking at all the previous postings, I have come to the conclusion that it is immaterial what the box is made of so long as it is well insulated (Non flammable at the temperatures likely to be experienced) and of a size that is suitable fo the ammount of dough/bread that I and my oven can process at any one time.

I have seen the Brod and Taylor box (Circa $148) available in USA/Canada - I like the look of it but it seems just a little bit on the small side for me and I am not prepared to bay that sum of money for something which is not quite right/big enough for me.

I was buying cat food recently and couldnt help noticing, in the "Snakes and lizards" section of the store, some interesting equipment. There were low wattage heating pads and thermostats suitable for heating the boxes that the animals live in.                                             And guess what? The animals like to live within the same temperature range as my bread doughs.

And now (At last I hear you cry) to my question - Does any one have any experience of this heating system for bread proofing boxes.

Thanks in anticipation.



Nickisafoodie's picture

Hi Brian, a large carboard box, a 100 watt lamp and this $35 thermostat gadget works great for me...  you certainly could make an insulated box and do same but my temps help within 1-2 degrees simply with the box...

ananda's picture

Hi Brian,

Andrew Whitley first recommended these, if I'm not wrong.   There is humidity potential, and the standard holding temperature is 26*C!

All good wishes


Like this one:


tn gabe's picture
tn gabe

there are several write ups online detailing how you can convert a fridge or upright freezer into a curing chamber for fermenting sauasages. Would be a great proofer/retarder for the avid home baker, for around $200 depending on what you already own and your ability to scrounge.

On a roll's picture
On a roll

Dorrie Greenspan, protegee of Julia Child and cookbook author in her own right, just posted on her blog about the proofing box her husband (wonder if he's discovered TFL?) devised. Take a look:


Janetcook's picture

Here is a link to the one I made this past winter using a reptile cage, piece of plexiglass, ceramic heating bulb, reptile thermostat, indoor outdoor thermometer, small bowl of water and a computer fan.

Easy to construct tho' my box does need a permanent place to sit.  


  •  Inexpensive to build.
  • Made of glass so it is easy to clean plus leaven and loaves can be viewed without opening the door.
  •  Door  that opens like an oven.
  • Great conversation piece :-)


  • Needs a permanent  place to sit that is large enough to support it's weight.

That is the only con I have run into thus far and for me it is not a 'con' as I have space for it.

Have fun with your project.  I had fun building mine and love it!



sandydog's picture

Thank you very much, to Nick, Andy, tn gabe, On a roll and Janet for their helpful suggestions/links.

You have given me (And, no doubt, many others thinking along the same lines) sufficient information to be able to make a decision and get on with making my box.

Between you, you seem to have covered all options from the cheapest to the (Relatively) expensive as well as considerations regarding available space, existing appliances/equipment and convenience viz a viz fitting in with family living arrangements and room decorations etc.

As a result, I have now entered detailed (And rather delicate) negotiations with my "Senior domestic manager" Katie (A sugar crafter - makes wonderful celebration cakes) to see which is the most appropriate option, as I would like to minimise disruption to her enjoyment of our home environment whilst maximising results in my own home bread making.

As a relatively new member of this forum/site I want to say what a fantastic vehicle it is for sharing ideas and airing differences of opinion. The more mature I become, the more I realize that there is more than one valid opinion, or way of doing things - And that it often depends on where you are in the world, as conditions and available equipment/ingredients seem to vary so much.

I love the tolerant and respectful way the site is run and hope to contribute in my own small way in the future.

Thanks again, everyone, for your invaluable assistance.



Our Crumb's picture
Our Crumb

FWIW, before kitchen temps rose to their current summer ~80˚F hereabouts, I inverted a large (1.5' x 1.5' x 2.5'), industrial styrofoam box on top of a seedling heating mat (available from lots of places, Gardeners Supply, Charlies Greenhouses, etc. -- used only for a few weeks here very Spring).  I can tweak the interior temp by raising the box off the mat varying distances.  I  set a porcelain tile on top of the mat and a few mason jar rings on top of that, to hold some heat and to keep the banneton from directly contacting the warm tile, respectively.  One could use a cooling rack of course, but those are in short supply here, used elsewhere.  I got the box from a biotech lab across the hall from mine that takes weekly delivery of DNA sequencing reagents in dry ice in these boxes (and then bins them).  So that was fortuitous.  If you're near a university that has a lab like that, they're likely throwing away these boxes regularly.  A cheapo supermarket styrofoam picnic cooler would do (no need for fancier plastic picnic cooler).  But the lids of these biotech reagent boxes are handy:  they're in two parts  that allow one to suspend an ice pack (also from the Tuesday deliveries) in the top to hold a very useful 50-60˚F all night in the box (upright, in this case), for gentle dough retards and (hopefully soon) desem building. 



mwilson's picture

I might as well chime in here since I have a DIY solution. I use an aquarium heater to create a warm pool that my dough sits in. Although my particular setup works for this small dough you could easily scale it up or just put dry boxes on top and calibrate the temperature accordingly.

Keeping my Sourdough at 28C.

Nickisafoodie's picture

CharlieZ, my post above with the link therin shows a recent post about a device I use that cost $35.  It can maintain hot or cold temps, a switch for either.  If you want cold and you have a room airconditioner or a spare refrigerator, either can plug into the device and you set your temp - and the AC or fridge will come on when it needs to cool and off when your set point is reached.